Most modern electronic systems are powered by one or more voltage regulators that provide regulated output power to the system. A typical voltage regulator includes a feedback signal extending from the power input to the system back to the DC/DC converter. The feedback signal is used in the voltage regulator to regulate the output power at the input to the system, thereby reducing error in the regulated output that might be caused by conduction losses between the voltage regulator and the system.
FIG. 1 shows a typical conventional feedback system used with a voltage regulator 12 and electronic system 14. An integrated circuit 16 may include the voltage regulator 12 and connect via a pin 17 to external filter components such as an output inductor 18 and output capacitor 20. A feedback signal 22 from the regulated output, Vout, may connect to the voltage regulator via a pin 19. The feedback signal 22 is typically received from a junction of the output inductor 18 and the output capacitor 20 so that gain and phase associated with the filter components is included within the control loop of the voltage regulator 12. The feedback signal may additionally be obtained from a point nearer to the input to the electronic system 14 to minimize the error caused by parasitic effects such as conduction losses and leakage inductance.
Although, sensing the junction of the filter components to generate the feedback signal may improve the stability and accuracy of the regulated output of the voltage regulator 12, if the line carrying the feedback signal becomes electrically degraded, the regulated output may drift outside of the regulation limits causing the voltage regulator 12 to shutdown.